import java.util.*;

abstract class Base {
    private int x;
    private int y;

    public abstract int avg();

    public abstract int sum();


    public int getX() {
        return x;
    }

    public void  setX(int x) {
        this.x = x;
    }

    public int getY() {
        return y;
    }

    public void setY(int y) {
        this.y = y;
    }

    public int calculate() {
        if (avg() == 0) {
            return 0;

        } else {
            return sum() / avg();
        }
    }

}

class Sub extends Base {
    @Override
    public int sum() {
        return super.getX()+super.getY();
    }

    @Override
    public int avg() {
        return (super.getX()+super.getY())/2;
    }
}



    public class Test {

    public static void main(String[] args) {

        Base base = new Sub();
        Scanner scanner = new Scanner(System.in);
       while (scanner.hasNextInt()){
        int x = scanner.nextInt();

        int y = scanner.nextInt();
        base.setX(x);
        base.setY(y);
        System.out.println(base.calculate());
       }
    }
}